17-63971191-C-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM5PP3_Strong

The NM_000334.4(SCN4A):c.674G>A(p.Arg225Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000268 in 1,564,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R225W) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

SCN4A
NM_000334.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.91

Variant links:

Genes affected

SCN4A (HGNC:10591): (sodium voltage-gated channel alpha subunit 4) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit with 24 transmembrane domains and one or more regulatory beta subunits. They are responsible for the generation and propagation of action potentials in neurons and muscle. This gene encodes one member of the sodium channel alpha subunit gene family. It is expressed in skeletal muscle, and mutations in this gene have been linked to several myotonia and periodic paralysis disorders. [provided by RefSeq, Jul 2008]

SCN4A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1

In a transmembrane_region Helical; Name=S4 of repeat I (size 16) in uniprot entity SCN4A_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_000334.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN4A	NM_000334.4 link	c.674G>A	p.Arg225Gln	missense_variant	Exon 5 of 24	ENST00000435607.3	NP_000325.4	P35499

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN4A	ENST00000435607.3 link	c.674G>A	p.Arg225Gln	missense_variant	Exon 5 of 24	1	NM_000334.4	ENSP00000396320.1		P35499

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

151944

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000194

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000946

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000282

AC:

AN:

177494

Hom.:

AF XY:

0.0000317

AC XY:

AN XY:

94654

show subpopulations

Gnomad AFR exome

AF:

0.000101

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000773

Gnomad SAS exome

AF:

0.0000421

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000273

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000276

AC:

AN:

1412814

Hom.:

Cov.:

AF XY:

0.0000244

AC XY:

AN XY:

698116

show subpopulations

Gnomad4 AFR exome

AF:

0.0000617

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000539

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000304

Gnomad4 OTH exome

AF:

0.0000342

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152062

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74312

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000194

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000946

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.0000170

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Hyperkalemic periodic paralysis

Uncertain:1

Nov 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 225 of the SCN4A protein (p.Arg225Gln). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with clinical features of autosomal recessive congenital myopathy or myasthenic syndrome (PMID: 36099689). ClinVar contains an entry for this variant (Variation ID: 477431). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt SCN4A protein function with a positive predictive value of 80%. This variant disrupts the p.Arg225 amino acid residue in SCN4A. Other variant(s) that disrupt this residue have been observed in individuals with SCN4A-related conditions (PMID: 26700687, 36099689), which suggests that this may be a clinically significant amino acid residue. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.56

BayesDel_noAF

Pathogenic

0.57

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.99

Eigen

Pathogenic

0.96

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

0.84

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

0.94

MutationAssessor

Pathogenic

4.3

PrimateAI

Pathogenic

0.90

PROVEAN

Uncertain

-3.3

REVEL

Pathogenic

0.97

Sift

Pathogenic

0.0

Sift4G

Uncertain

0.0070

Polyphen

1.0

Vest4

0.96

MutPred

0.96

Loss of MoRF binding (P = 0.0202);

MVP

0.97

MPC

0.98

ClinPred

0.97

GERP RS

4.2

Varity_R

0.87

gMVP

0.98

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over